As the nanotechnology field is developed, the demands on measuring capabilities is increased, and the wish to be able to perform measurements with atomic resolution has increased dramatically over the past years. In this field, electron microscopes are commonly used instead of common light microscopes, since electrons has a smaller wavelength than light, and hence can resolve much smaller structures. Different types of electron microscopes, such as transmission electron microscopes (TEM) and also scanning electron microscopes (SEM), partly solves the above-mentioned problems and demands. Moreover, different scanning probe technologies, such as scanning probe microscopy (SPM), scanning tunnelling microscopy (STM) and atomic force microscopy (AFM) have been developed, and these also solve some of the above problems.
Force interactions between nano-particles has been studied for a long time. One technique for this is Transmission Electron Microscopy (TEM), in which direct visualisation of the interacting particles gives understanding of the interaction. However, this method only gives a visual presentation of the interaction, and its use is therefore limited. One improved method and device for studying force interactions between nano-particles is the TEM-STM microscope (transmission electron microscope-scanning tunnelling microscope). In this kind of microscope a scanning tunnelling microscope (STM) is placed inside a transmission electron microscope (TEM), enabling simultaneous measurements of sample structure as well as electrical properties of the samples, such as conductance. This microscopy technique is much helpful when studying certain aspects of particle interaction. However, there is still a need for extending the range of experiments that can be performed, and thereby gaining a deeper understanding of the nature of matter.
One such improved measurement method is disclosed in the patent document WO 01/63204. This document discloses a transmission electron microscopy device, being combined with an atomic force microscopy device, positioned within the transmission electron microscope. This device enables atomic force microscopy (AFM) measurements to be made in a TEM environment, thereby enabling simultaneous TEM and AFM measurements, for investigating the relationship between the interaction force between and the geometry of interacting particles.
Recently, considerable amount of research has been directed towards the measurement of mechanical properties, such as hardness, delamination, tribology and so on. For this reason, so called nanoindentation measurement devices has been developed. In a nanoindentation device, a sample to be studied is positioned in a sample holder, and an indenter tip is arranged to be pressed onto the surface of the sample. An example of such a nanoindentation device is disclosed in the article “Quantitative in situ nanoindentation in an electron microscope”, Minor et al, Applied Physics letters, Vol 79, no 11, 10 Sept 2001, pp 1625-1627. This device comprises a sample holder holding a sample, and a diamond indenter. The indenter is mounted on a piezoceramic actuator, which both controls its position and forces it to the edge of the sample. The characteristics of the piezoceramic actuator is also used to indirectly calculate the force of the nanoindentation, by measuring the displacement of the indenter and the voltage applied to the piezoceramic actuator. However, the actuator characteristics must be calibrated carefully in order to be able to calculate a correct value of the force, and hence a more straight-forward measurement device for force measurements in for use in for example nanoindentation measurements is desired.